Great Lakes to Gulf Logo
Great Lakes to Gulf
Tracking nutrients in the Mississippi River Basin
Getting StartedResources
Contact

Monitoring Locations

Related GIS Layers

Legend for HUC 8
Legend for HUC 4
Legend for HUC 2
Legend for Green Infrastructure Locations
Legend for Density of Green Infrastructure Practices by HUC12
Legend for Corn fraction per HUC8 (2012–2020)
Legend for Soybean fraction per HUC8 (2012–2020)
Legend for Tile Drainage Fraction per HUC8 (2012)
Legend for Nitrate Loading in June (g N/m²) (base)
Legend for Nitrate loading in June (g N/m^2) (increase tile fraction by 20%)
Legend for Nitrate loading Absolute Increase (g N/m^2) (increase tile fraction by 20%)
Legend for Nitrate Loading Relative Increase (%) (increase tile fraction by 20%)
Legend for Nitrate loading in June (g N/m^2) (increase tile fraction by 30%)
Legend for Nitrate loading Absolute Increase (g N/m^2) (increase tile fraction by 30%)
Legend for Nitrate Loading Relative Increase (%) (increase tile fraction by 30%)
Legend for Subsurface Tile Drainage
External Layer Sources
USDA Cropland Data Layer
Source: USDA National Agriculture Statistics Survey: CroplandCROSUpdated: October 2025
NOAA National Centers for Environmental Information: Gulf of America Hypoxia Watch
Source: NOAAUpdated: October 2025
USGS 2012 SPARROW Models for the Midwest
Source: USGSUpdated: October 2025
US EPA: How’s My Waterway?
Source: US EPAUpdated: October 2025